It needs to be done, Betsy is one of the coolest, most badass X-Men in this 'viners humble opinion. However she doesn't seem to ever get the respect that she deserves; so here are the feats I have of her. They're organized by series, I'll put issue numbers where I have them and a short elaboration on what's happening and the context of the feat if required. After I finish posting feats, feel free to contribute to this thread if you have anything to add.
Captain Brittan (Vol 2)
Captain Brittan #6 Betsy kills with Telepathy; I believe this is the first instance of her taking a life. Anyway Kaptain Britian (an alternate Universe version of Captain Britian) was attempting to rape her and she fried his brain killing him.
Uncanny X-Men (Vol 1)
Uncanny X-Men #213 The issue that started it all; Betsy had been a hangaround with the X-Men and New Mutants, she was determined to prove herself worthy of the team. After using Cerebro and recieving a nasty feedback from Sabertooth's bloodthristy instincts. She manages to hold him off long enough for the X-Men to arrive penetrates his defenses and gets valuable intel on the maruders. For her courage and usefulness she's awarded a spot on the team.
Uncanny X-Men # 214 Betsy uses a psi-bolt and knocks Wolverine on his butt.
Uncanny X-Men # 216 Betsy uses her telepathy to scan all of Muir Island. Keep in mind these are early showings when her powers were not nearly as developed as they are now.
Uncanny X-Men #217 Betsy in a training exersice with Longshot, Dazzler and Rogue. Even with Rogue's well known telepathic resistance Betsy is able to monitor her thoughts and cast a telepathic illusion. She also briefly takes over Dazzler's mind and uses her powers against Longshot. Later she goes over the fight with Banshee.
Uncanny X-Men # 218 Betsy fires a psi-bolt through Juggernauts telepathically impenetrable helmet managing to stun him and then K.O's him after Dazzler manages to remove the helmet completely.
Uncanny X-Men 219 Betsy preforms an (off panel) mindwipe on Havok.
Uncanny X-Men 225 Betsy uses a telepathic illusion on Super Sabre and attempts to telepathically induce Blob (she's interrupted).
Uncanny X-Men 230 Betsy telepathically shields Longshot and Psi-Links the X-Men.
Uncanny X-Men 236 Betsy preforms a mass telepathic interrogation. We also get to see hints of the more ruthless side that'll later on become a hallmark of her character.
Uncanny X-Men 237 She uses her psi bolts to knock out some fodder.
Uncanny X-Men 238 Betsy possess telepathically forces Mindwipe to use his powers to restore Logan and Rogue/Carol Danvers. Use's a 'Psi-Web' (psychic surgery) to edit memories.
Uncanny X-Men 239 Casts a TP illusion on Rogue (again :P) dodges a blow from Piotr, gets slugged by him ( a good durability feat for her old armor) and knocks Rogue out with a Psi-bolt.
Uncanny X-Men 240 Uses her TP to alter Scrambler's perceptions (she really seems to like using TP illusions).
Uncanny X-Men 242 Uses her telepathy to block access to Jean Grey's powers (Jean only had TK at the time) Then mindlinks with Jean and amplifys her latent TP.
Uncanny X-Men 243 One shots Sabertooth with her TP. Betsy's become much more proficient with her TP since their first encounter some 30 issues ago.
Uncanny X-Men 247 Uses TP against Nimrod/Master Mold. Impressive in that TP usually doesn't affect techno-organic beings.
Uncanny X-Men #257: A bit of background Betsy was captured by the Hand in UXM 255 and brainwashed by them in UXM 256 (which was also the first appearance of her iconic ninja-thong costume), at the end of that issue she swore her loyalty to the Hand and The Mandarin, she was employed as a assassin and given the title 'Lady Mandarin' (because she wielded the Mandarin's rings) this was also the debut if her trademark Psi-Knives and newly enhanced fighting skills courtesy of The Hand. She also switches ethnicity from British Caucasian to Japanese, this will be elaborated on in a few years in the pages of X-Men. Okay background over, In this issue Betsy shows off her new h2h skills, uses her psy knives to kill a hand genin and bests (a somewhat weakened) Wolverine in combat.
Uncanny X-Men #258: Wolverine snaps Betsy back to her right mind while they are psychically linked (she's attempting to brainwash him for The Hand), they fake out the Mandarin and Betsy has a brief scuffle and a struggle of wills with the Mandarin before Wolverine saves the day.
Uncanny X-Men #261 Gets into a short scuffle with SHIELD agent Blindside and uses yet another telepathic illusion. (Out of Order)
Uncanny X-Men # 268 Betsy, Wolverine and Jubilee take out some Hand ninjas, she preforms a pyschic interrogation and info dumps the results into Jubilee's brain, gets into a short scuffle with Havok and stabs him with her Psy-Knife
Uncanny X-Men #273 Betsy's first encounter with the Shadow King, they don't fight though, Betsy uses her Psy-Knife to save Jean from him though.
Uncanny X-Men #322 Betsy uses her Psy-Knife on a wounded Juggernaut (thanks to Onslaught).
Uncanny X-Men # 323 Betsy shows off some agility in the Danger Room with Archangel
Uncanny X-Men #324 Uses her TP to go into Gambit's mind without his permission.
Uncanny X-Men # 328 Gets into a fight with Sabertooth, when he tricks Boom-Boom into freeing him. A good skill showing on her part, ultimately though Sabertooth's TP immunity (which he had at the time because of brain injuries he had sustained against Wolverine) let's him take the fight, he guts her and escapes.
Uncanny X-Men #333 Wolverine, Doctor Strange and Angel journeyed to another dimension and managed to infuse Betsy's soul with a power source called the Crimson Dawn (over the course of UXM 329-330), it saved her life, enhanced her fighting abilities and added shadow teleportation and shadow melding to her powerset. It most notably gave her a distinct red tattoo/marking over the left side of her face. She has a quick sparring session with Angel and he comments on her enhanced fighting prowess. She also gets a psychic warning that Juggernaut is approaching.
Uncanny X-Men #338 Betsy shows off her new shadow powers, a side effect of the Crimson Dawn was it deadened her emotions and started overwriting her personality.
Uncanny X-Men #349 Confrontation with Maggot, uses her shadow teleportation to get the drop on him.
Uncanny X-Men #385 Use's her TK to deflect a charging Beast, A charging Colossus and uses her TK Katana to slash through a bank vault door. This was after Betsy lost her TP and exchanged powers with Jean *more feats to come from this era in other X-Books*.
Uncanny X-Men #458 This was during the time after the Crimson Dawn, when Betsy's brother resurrected her. She became completly immune to TP and reality warping during this time. Betsy uses her TK Katana to break through a psychic block Rachel put on the X-Men's powers and demonstrates the cutting power of her TK blade.
Uncanny X-Men #460 Takes on a simulation of Sabertooth and schools it handily, uses her TK to enhance her striking power
Uncanny X-Men #467 Uses her TK to crush compress bullets to denser projectiles
Uncanny X-Men #468 Her TK Katana breaks through mind control (and as we'll find out later psychic sheilding)
Uncanny X-Men #512 Betsy explains that her powers have changed (again) she begins regaining her telepathy, at this point she can only use it to 'suggest'. Later on she uses it to casts a psychic illusion.
X-Men: Die By The Sword
Issue 5: Betsy gets into a fight with Merlyn (yes that Merlyn) and beats him down pretty hardcore, she also forms a TK Bat.
Exiles #91 Betsy gets a rematch against Sabertoot (sort of). Betsy's actually facing off against AOA Sabertooth and shows how her fighting skills have grown over the years, she handles him solidly, she also exhibits a new facet to her powers; she's invisible to electronic equipment (thanks to her brother Jamie).
Exiles #92/93 Betsy uses her TK to render herself invisible. An AU Reed Richards states that her TK is molecular in it's control to preform such a feat
Exiles #98 Betsy uses her TK to shield an ally, decent reaction feat.
New Exiles ??? I accidently deleted the issue number with this feat but I'm pretty sure it's a New Exiles feat anyway it's a pretty good one, Betsy shows off some h2h and TK constructs (a shield and her trusty katana).
New Exiles 9: Using Magic and Science Betsy gets 'a lifetime' of training with Ogun to enhance her h2h skills, unfortunetly this also had the effect of allowing that world's version of Psylocke who was inhabiting her psyche begin to supplement her personality over Betsy's.
AvX: VS (Vol 1.)
Issue 4: Daredevil vs Psylocke, there's a touch of CIS (how come she didn't utilize her TK?) and WIS, her attempt to use TP overloads her because his hyper senses overwhelm her, despite the fact that she's mind linked with Wolverine with no problem before and he also has hyper senses. Despite that it's a solid outing for her that ends in a draw.